1. Field of the Invention
The invention relates to a hearing system including an earpiece comprising a shell and an insert unit detachably connected to the shell.
2. Description of Related Art
A system of the type to which the invention relates may be used for wireless communication with other persons if the insert unit is an active electronic unit which is connected via a cable to an external electronic unit. Typically, the communication is bidirectional, with the active unit then comprising at least one microphone for capturing the user's voice. The external electronic unit typically comprises a mobile phone or a radio device. The external audio signals received by the external communication device are supplied to the loudspeaker of the active unit, and the audio signals captured by the microphone(s) of the active unit are transmitted to a corresponding wireless communication device used by another person. In addition to the communication function, the hearing system may provide for a hearing protection function, which requires an appropriate design of the earpiece which has to act as a hearing protection earplug. In this case, for enabling a noise level dependent dynamic hearing protection function, the active unit may be provided with a microphone for capturing ambient sound, and the external unit may be provided with an appropriate audio signal processing unit which supplies the processed ambient audio signals to the loudspeaker of the active unit. There are also cases in which the system comprises only the dynamic hearing protection function, but not a bidirectional communication function.
In the simplest case, for realizing a passive hearing protection function, the insert unit comprises at least one acoustic attenuation filter, but no electronic components. By selecting different filters, the attenuation may be individually adjusted to some extent.
The shell of the earpiece, in particular, if a hearing protection function is desired, may be manufactured as a customized shell having a shape which is adapted to the individual shape of the user's ear, usually by manufacturing the shell according to an impression taken from the user's ear. Customized shells provide for optimal retention within the user's ear and for optimized acoustic sealing. While customized earpieces may provide for improved retention and sealing properties compared to generic earpieces (i.e. earpieces having a standard shape), manufacturing of customized earpieces is more complicated, in particular because it involves participation of the user for taking an impression of the user's ear.
Examples of customized earpieces for hearing protection systems comprising bidirectional communication functions are found in European Patent Application EP 1 674 059 A1, International Patent Application Publication WO 2007/082579 A2 and U.S. Pat. No. 6,661,901 B1. An example for an active hearing protection system without bidirectional communication function is described in European Patent Application EP 1 071 307 A1. Further examples of earpiece communication systems are found in International Patent Application Publication WO 2009/047369 A2.
It is known, for example, from German Utility Model DE 297 18 483 U1, European Patent Application EP 1 448 014 B1, and International Patent Application Publications WO 2007/014950 A2 or WO 2007/147416 A1, to provide hearing aids to be worn at least partly in the ear canal with an elastic C-shaped bow-like element for improving retention of the shell in the ear canal, wherein the retention force is provided by the elastic deformation of the retention element which engages with the concha when worn by the user. U.S. Patent Application Publication US 2006/0067556 A1 relates to an earpiece comprising a bow-like retention element and a sound channel, which may be connected in a releasable manner with an acoustic device which may be a hearing aid or a wireless communication device. The wireless communication device may form a wireless headset for a mobile phone.
European Patent Application EP 1 364 553 B1 relates to an earpiece comprising an elastic concha bow and a sound channel as well as a microphone and a loudspeaker which are connected via a cord with an external audios signal processing unit for realizing a headset for wireless communication.
European Patent Application EP 1 377 113 A1 relates to a headset comprising an earpiece which carries a boom microphone and comprises an elastic concha bow.